Anthropometrics II Rad Zdero, Ph.D. University of Guelph.

Anthropometrics II

Rad Zdero, Ph.D.University of Guelph

• Anthropometric Data Tables

• Example• Using and Generating

Anthropometric Data

• Ergonomic Design Principles

• Ergonomic Design Approach

Outline

AnthropometricData Tables

Figure 1. Static BodyFeatures. Structural Dimensions for U.S.Adults (1989).

(see also Figure 2 andTables 1 to 4 for Values)

[source: Kroemer, 1989]

Figure 2. Percentile of Population Group

Normal or GaussianData Distribution

No. ofSubjects

5th percentile = 5 % of subjectshave “dimension”below this value

50 %95 %

Dimension(e.g. height,weight, etc.)

Table 1 - U.S. Adult Civilians (1989)

Segment Gender 5 th Percentile

50 th Percentile

95 th Percentile

1. Stature M

F

161.8 cm

149.5

173.6 cm

160.5

184.4 cm

171.3

2. Eye Height M

F

151.1

138.3

162.4

148.9

172.7

159.3

3. Shoulder Height

M

F

132.3

121.1

142.8

131.1

152.4

141.9

4. Elbow Height

M

F

100.0

93.6

109.9

101.2

119.0

108.8

5. Knuckle Height

M

F

69.8

64.3

75.4

70.2

80.4

75.9

See “Static Body Features” Figure 1 for exact dimension

Table 2 - U.S. Adult Civilians (1989)

Segment Gender 5 th Percentile

50 th Percentile

95 th Percentile

6. Height (sit) M

F

84.2 cm

78.6

90.6 cm

85.0

96.7 cm

90.7

7. Eye Height (sit)

M

F

72.6

67.5

78.6

73.3

84.4

78.5

8. Elbow Height (sit)

M

F

19.0

18.1

24.3

23.3

29.4

28.1

9. Thigh Clearance (sit)

M

F

11.4

10.6

14.4

13.7

17.7

17.5

10. Knee Height (sit)

M

F

49.3

45.2

54.3

49.8

59.3

54.5

See “Static Body Features” Figure 1 for exact dimension

Table 3 - U.S. Adult Civilians (1989)

Segment Gender 5 th Percentile

50 th Percentile

95 th Percentile

11. Buttock-to-Knee (sit)

M

F

54.0 cm

51.8

59.4 cm

56.9

64.2 cm

62.512. Thigh-to-Heel Height (sit)

M

F

39.2

35.5

44.2

39.8

48.8

44.3

13. Chest Depth (stand)

M

F

21.4

21.4

24.2

24.2

27.6

29.7

14. Elbow-to-Elbow (sit)

M

F

35.0

31.5

41.7

38.4

50.6

49.1

15. Hip Width (sit)

M

F

30.8

31.2

35.4

36.4

40.6

43.7

See “Static Body Features” Figure 1 for measured dimension

Table 4 - U.S. Adult Civilians (1989)

Segment Gender 5 th Percentile

50 th Percentile

95 th Percentile

Weight (kg) M

F

56.2 kg

46.2

74.0 kg

61.1

97.1 kg

89.9

See “Static Body Features” Figure 1 for measured dimension

Note for Tables 1-4: Due to anatomical reasons, Male data islarger than Female data at all %iles, with the exception of#13 (Chest Depth) and #15 (Hip Width), which shows a

reversal of this trend.

Body Segment Lengths

Limb

White Male White Female

(Percentile) (Percentile)

5 th 50 th 95 th 5 th 50 th 95 th

Upper Arm 28.6 30.4 32.3 26.1 27.8 29.5

Forearm 25.9 27.5 29.2 22.7 24.1 25.5

Thigh 40.4 43.2 46.1 36.9 39.5 42.1

Shank 38.9 42.1 45.3 34.7 37.4 40.0

[all values are in centimetres]

L

Joint or HingeSegment

Body Segment Density

Body Segment Year = 1860 Year = 1955

Head and Neck 1.11 g/cm3 1.11 g/cm3

Trunk -- 1.03

Upper Arm 1.08 1.07

Forearm 1.10 1.13

Hand 1.11 1.16

Thigh 1.07 1.05

Lower Leg 1.10 1.09

Foot 1.09 1.10

Density = Mass / Volume Human Segment Density ~ 1 g/cm3

Body Segment Weights

Main Segment as % of Total Body Weight

Individual Segment as

% of Main Segment

Head and Neck = 8.4 % Head = 73.8 %

Neck = 26.2 %

Torso = 50 % Thorax (chest) = 43.8 %

Lumbar = 29.4 %

Pelvis = 26.8 %

One Total Arm = 5.1 % Upper Arm = 54.9 %

Forearm = 33.3 %

Hand = 11.8 %

One Total Leg = 15.7 % Thigh = 63.7 %

Shank = 27.4 %

Foot = 8.9 %

Centre of Gravity

Relative locationof C-of-G’s onbody segments.See the C-of-G%-iles in the nexttable [Dempster, 1955]

Centre of Gravity

Center of Gravity/Segment Length = L1/L2 (%)

Segment Year = 1889

1955 1969

Total Body -- -- 41.2 %

Head -- 43.3 % 46.6

Arm 47 % 43.6 51.3

Forearm 42.1 43 39

Hand -- 49.4 --

Total Arm -- -- 41.3

Forearm & Hand 47.2 -- --

Thigh 44 43.3 --

Calf (= Shank) 42 43.3 37.1

Foot 44.4 42.9 44.9

Total Leg -- 43.3 --

Calf & Foot 52.4 43.7 47.5

C-of-G willnormally be closer

to the “thicker” proximal end

of the segment.

L1 L2

Distal End

Proximal End

[modified from Winter, 1992]

Segment

Head & Neck

C-of-G / SegmentLength

0.50

0.506

0.430

0.436

0.433

0.433

0.500

0.500

Hand

Forearm

Upper Arm

Thigh

Leg

Foot

Trunk

Center of Gravity/Segment Length = L1/L2 (%)

C-of-G willnormally be closer

to the “thicker” proximal end

of the segment.

L1 L2

Distal End

Proximal End

Radius of Gyration/Segment Length = K/L (%)(Cadaver Experiments)

Body Segment From Proximal End

From Distal End

Head, Neck, Trunk 49.7 % 67.5 %

Full Arm 54.2 64.5

Forearm 52.6 64.5

Hand 58.7 57.7

Forearm and Hand 82.7 56.5

Thigh 54 65.3

Shank 52.8 64.3

Foot 69 69

Shank and Foot 73.5 57.2

K

L

Distal End

Proximal End

K

Example – Anthropometric Forearm Data

Purpose• Become accustomed to Generating and Using

Anthropometric Data tables and formulas.Steps (Use ruler or tape measure for length measurement)1. Measure length, L, of forearm (elbow to wrist) and diameter,

d, about half way along length2. Calculate approx. forearm volume, V = (d/2)2L3. Calculate forearm mass, m, in two ways … (do they match?)

• using m = D x V and density from Density Table• using “Body Segment Weights” table

4. Calculate forearm C-of-G using C-of-G/Length ratio table5. Calculate forearm radius of gyration, K, using forearm

length, L, and “Radius of Gyration” table

Forearm Data TableDimension Symbol Value

(female)

Value

(male)

Length L

Closest %ile for Length %

Diameter d

Volume V

Mass (from density formula, D = m/V)

m

Mass (from “Body Segment Weight” table)

m

C-of-G (from elbow) C-of-G

Radius of Gyration

(from elbow)

K

Ergonomic Design Principles1. Designing for the Average• There is no “average” person• Very difficult to find person who is average in more than a few

dimensions (e.g. avg. height may not necessarily mean avg. leg length and arm length)

• Designing for the average can be an over-simplification• Only to be done after careful evaluation (e.g. very specific

subgroup)

e.g. Clothing Study (n = 4096 people)Center 30% was taken as Avg. Percentile, BUT…Only 26% were of Avg. HeightOnly 7.4% had Avg. Chest CircumferenceOnly 3.5% had Avg. Sleeve LengthOnly 0.07% had Avg. Waist CircumferenceAnd 0% had Avg. Foot Length

2. Designing for the ExtremesPrinciple

• Try to accommodate entire population groupMaximum Levels

• e.g. doorways, size of escape hatches on military aircraft, strength of ladders and workbenches

Minimum Levels• e.g. distance of control button from operator, force

required to operate control lever or button Practical Design Range

• use 5th and 95th percentiles of pop. group as extremes• use smallest female and largest male

Questions• Effects on those excluded?• Can we restrict users to a certain pop. group?

3. Designing for AdjustmentPrinciple

• Try to allow for adjustments in size, shape, position, intensity, and duration of the product, device, procedure, or system to accommodate unexpected circumstances

Practical Design Range• Common to use 5th %ile female and 95th %ile male• Results in accommodation of 95% (not 90%) of 50/50

male/female pop. group because of overlap in male and female body dimensions

Examples• Car seats, desk height, footrests, office furniture

Questions• Use: one shot vs. continual?• Use: one user or shared?• Ease of and Training for using “adjustments”?• What happens if design range misused?

Ergonomic Design Approach

1. Determine important body dimensions

2. Define population group (men, kids, Swedes?)

3. Decide on which design principles will be used (design for extremes, average, adjustment?)

4. Select which sub-group of pop. group will be designed for (5th, 50th, 73rd, %ile?)

5. Extract values from Anthropometric Tables

6. Add dimensional allowances for any clothing, equipment, safety precautions, and task performance.

7. Build “prototype” or “mock up” of product, device, procedure, or facility.

8. Test prototype with human subjects.

Sources Used• Chaffin et al., Occupational Biomechanics, 1999.• Dempster, Space Requirements of the Seated Operator,

1955.• Hay and Reid, 1988.• Kreighbaum & Barthels, Biomechanics: A Qualitative

Approach for Studying Human Movement, 1996.• Kroemer, “Engineering Anthropometry”, Ergonomics,

32(7):767-784, 1989• Sanders and McCormick, Human Factors in Engineering

and Design, 1993.• Moore and Andrews, Ergonomics for Mechanical Design,

MECH 495 Course Notes, Queens Univ., Kingston, Canada, 1997.

• Oskaya & Nordin, Fundamentals of Biomechanics, 1991.• Winter, Biomechanics of Human Movement, 1992.